clear all
clc 
k=linspace(1,20,20);
n=1.22*10^11*(1.109*10^5*(0.5*exp(-0.28*k-6.4/3)+exp(-(0.28+2/3)*k-8.8/3)/(1-exp(-2/3*k-0.8)))-1);
figure
plot(k,n)
xlabel('k')
ylabel('n')